Wow! Lovely to see a smile from Vikki. Well done on that.
However, I don't like the lighting. It looks like hard light, close to the camera and very square on to her face, creating unappealing hotspots and sheen almost as though the flash was fired on camera. I know it wasn't, but I don't think the lighting is flattering on the model and the background just seems left to make do with leftovers. I can't see any detail in her hair other than strands at the back, and no detail in the dress.
I like the lighting on the face for #2, but the top of her head looks a little hot and her hair looks a little messy around that bright area. Unfortunately the brightness draws the eye. That OOF fingers are, sadly, also distracting.
#3 has nice engagement between eyes and camera. I like the expression too. I think the fingers sprouting out of the bottom of the frame seem slightly odd. I'm not sure if we need to see more of the hand or the fingers repositioned. It just looks somehow not quite right.
#4 seems to have a lot of shadow area in the background that isn't contributing much. I'd be tempted to have composed tighter on Vikki or to maybe throw some more interesting lighting into that dark corner - perhaps some colour. The way she is posed has created a rather peculiar shape (shadow?) running down fom the top of her right shoulder to her right boob.
#5 isn't doing much for me. There's too much dead space above her and the thumb is chopped off. However, there does seem to be slightly better separation between model and background, at least in the top half of the image. Lower down it all seems to have merged into a shadowy abyss.
Apart from #2 I think they might all benefit from some rim lighting to make hair and the model as a whole stand out from the background. There are details on the models which are blending and almost disappearing into the background. #1 and #2 look a little soft to me. I don't know if that's down to the shooting or the processing, but they lack crispness and definition. The others aren't so soft, but they seem just slightly to lack punch and pop.
Hard to pick a winner, but I think it would be #4 if you could disguise that mark on her chest. #1 is my least favourite, with the lighting looking to my untrained eye rather like the results from a point and shoot.